Patterned metal articles, such as printed circuit boards, have many uses in the electronics industry. Printed circuits may be made by applying pressure with a heated die to metallic particles on an adhesive-coated substrate. Metal particles may also be mixed with a curable organic binder, and applied to a substrate using an adhesive layer, heat and pressure. Printed circuits may also be produced by embedding conductive granules mixed with an inorganic matrix material into a heat-softenable substrate. Silk screening methods may also be used to apply mixtures of organic materials and conductive particles to substrates, and compositions including metallo-organic decomposition compounds and metallic particles may also be silk screened on a substrate and heated to form a circuit pattern.
The adhesives and organic binders in these compositions are poor conductors of electricity, and, when mixed with metallic particles, reduce the overall conductivity of the resulting circuit pattern. The use of inorganic and metallo-organic compounds is limited to specific combinations of materials and particular substrates, and requires high processing temperatures.